NAME

tecla, teclarc - The user interface provided by the Tecla library.

DESCRIPTION

This man page describes the command-line editing features that are
available to users of programs that read keyboard input via the Tecla
library. Users of the tcsh shell will find the default key-bindings
very familiar. Users of the bash shell will also find it quite
familiar, but with a few minor differences, most notably in how forward
and backward searches through the list of historical commands are
performed. There are two major editing modes, one with emacs-like key-
bindings and another with vi-like key-bindings. By default emacs mode
is enabled, but vi mode can alternatively be selected via the user's
configuration file. This file can also be used to change the bindings
of individual keys to suit the user's preferences. By default, tab
completion is provided. If the application hasn't reconfigured this to
complete other types of symbols, then tab completion completes file-
names.

KEYSEQUENCENOTATION

In the rest of this man page, and also in all Tecla configuration
files, key-sequences are expressed as follows.
^A or C-a
This is a control-A, entered by pressing the control key at
the same time as the A key.
\E or M-
In key-sequences, both of these notations can be entered
either by pressing the escape key, then the following key, or by
pressing the Meta key at the same time as the following key. Thus
the key sequence M-p can be typed in two ways, by pressing
the escape key, followed by pressing p, or by pressing the
Meta key at the same time as p.
up
This refers to the up-arrow key.
down
This refers to the down-arrow key.
left
This refers to the left-arrow key.
right
This refers to the right-arrow key.
a
This is just a normal A key.

THETECLACONFIGURATIONFILE

By default, Tecla looks for a file called .teclarc in your home
directory (ie. ~/.teclarc). If it finds this file, it reads it,
interpreting each line as defining a new key binding or an editing
configuration option. Since the emacs keybindings are installed by
default, if you want to use the non-default vi editing mode, the most
important item to go in this file is the following line:
edit-mode vi
This will re-configure the default bindings for vi-mode. The complete
set of arguments that this command accepts are:
vi - Install key-bindings like those of the vi
editor.
emacs - Install key-bindings like those of the emacs
editor. This is the default.
none - Use just the native line editing facilities
provided by the terminal driver.
To prevent the terminal bell from being rung, such as when an
unrecognized control-sequence is typed, place the following line in the
configuration file:
nobeep
An example of a key binding line in the configuration file is the
following.
bind M-[2~ insert-mode
On many keyboards, the above key sequence is generated when one presses
the insert key, so with this keybinding, one can toggle between the
emacs-mode insert and overwrite modes by hitting one key. One could
also do it by typing out the above sequence of characters one by one.
As explained above, the M- part of this sequence can be typed either by
pressing the escape key before the following key, or by pressing the
Meta key at the same time as the following key. Thus if you had set the
above key binding, and the insert key on your keyboard didn't generate
the above key sequence, you could still type it in either of the
following 2 ways.
1. Hit the escape key momentarily, then press '[', then '2', then
finally '~'.
2. Press the meta key at the same time as pressing the '[' key,
then press '2', then '~'.
If you set a keybinding for a key-sequence that is already bound to a
function, the new binding overrides the old one. If in the new binding
you omit the name of the new function to bind to the key-sequence, the
original binding becomes undefined.
Starting with versions of libtecla later than 1.3.3 it is now possible
to bind keysequences that begin with a printable character. Previously
key-sequences were required to start with a control or meta character.
Note that the special keywords "up", "down", "left" and "right" refer
to the arrow keys, and are thus not treated as keysequences. So, for
example, to rebind the up and down arrow keys to use the history search
mechanism instead of the simple history recall method, you could place
the following in your configuration file:
bind up history-search-backwards
bind down history-search-backwards
To unbind an existing binding, you can do this with the bind command by
omitting to name any action to rebind the key sequence to. For
example, by not specifying an action function, the following command
unbinds the default beginning-of-line action from the ^A key sequence:
bind ^A
If you create a ~/.teclarc configuration file, but it appears to have
no effect on the program, check the documentation of the program to see
if the author chose a different name for this file.

FILENAMEANDTILDECOMPLETION

With the default key bindings, pressing the TAB key (aka. ^I) results
in Tecla attempting to complete the incomplete filename that precedes
the cursor. Tecla searches backwards from the cursor, looking for the
start of the filename, stopping when it hits either a space or the
start of the line. If more than one file has the specified prefix, then
Tecla completes the filename up to the point at which the ambiguous
matches start to differ, then lists the possible matches.
In addition to literally written filenames, Tecla can complete files
that start with ~/ and ~user/ expressions and that contain $envvar
expressions. In particular, if you hit TAB within an incomplete ~user,
expression, Tecla will attempt to complete the username, listing any
ambiguous matches.
The completion binding is implemented using the cpl_word_completions()
function, which is also available separately to users of this library.
See the cpl_word_completions(3) man page for more details.

FILENAMEEXPANSION

With the default key bindings, pressing ^X* causes Tecla to expand the
filename that precedes the cursor, replacing ~/ and ~user/ expressions
with the corresponding home directories, and replacing $envvar
expressions with the value of the specified environment variable, then
if there are any wildcards, replacing the so far expanded filename with
a space-separated list of the files which match the wild cards.
The expansion binding is implemented using the ef_expand_file()
function. See the ef_expand_file(3) man page for more details.

RECALLINGPREVIOUSLYTYPEDLINES

Every time that a new line is entered by the user, it is appended to a
list of historical input lines maintained within the GetLine resource
object. You can traverse up and down this list using the up and down
arrow keys. Alternatively, you can do the same with the ^P, and ^N
keys, and in vi command mode you can alternatively use the k and j
characters. Thus pressing up-arrow once, replaces the current input
line with the previously entered line. Pressing up-arrow again,
replaces this with the line that was entered before it, etc.. Having
gone back one or more lines into the history list, one can return to
newer lines by pressing down-arrow one or more times. If you do this
sufficient times, you will return to the original line that you were
entering when you first hit up-arrow.
Note that in vi mode, all of the history recall functions switch the
library into command mode.
In emacs mode the M-p and M-n keys work just like the ^P and ^N keys,
except that they skip all but those historical lines which share the
prefix that precedes the cursor. In vi command mode the upper case K
and J characters do the same thing, except that the string that they
search for includes the character under the cursor as well as what
precedes it.
Thus for example, suppose that you were in emacs mode, and you had just
entered the following list of commands in the order shown:
ls ~/tecla/
cd ~/tecla
ls -l getline.c
emacs ~/tecla/getline.c
If you next typed:
ls
and then hit M-p, then rather than returning the previously typed emacs
line, which doesn't start with "ls", Tecla would recall the "ls -l
getline.c" line. Pressing M-p again would recall the "ls ~/tecla/"
line.
Note that if the string that you are searching for, contains any of the
special characters, *, ?, or '[', then it is interpretted as a pattern
to be matched. Thus, cotinuing with the above example, after typing in
the list of commands shown, if you then typed:
*tecla*
and hit M-p, then the "emacs ~/tecla/getline.c" line would be recalled
first, since it contains the word tecla somewhere in the line,
Similarly, hitting M-p again, would recall the "ls ~/tecla/" line, and
hitting it once more would recall the "ls ~/tecla/" line. The pattern
syntax is the same as that described for filename expansion, in the
ef_expand_file(3 man page.

HISTORYFILES

Authors of programs that use the Tecla library have the option of
saving historical command-lines in a file before exiting, and
subsequently reading them back in from this file when the program is
next started. There is no standard name for this file, since it makes
sense for each application to use its own history file, so that
commands from different applications don't get mixed up.

INTERNATIONALCHARACTERSETS

Since libtecla version 1.4.0, Tecla has been 8-bit clean. This means
that all 8-bit characters that are printable in the user's current
locale are now displayed verbatim and included in the returned input
line. Assuming that the calling program correctly contains a call like
the following,
setlocale(LC_CTYPE, "");
then the current locale is determined by the first of the environment
variables LC_CTYPE, LC_ALL, and LANG, that is found to contain a valid
locale name. If none of these variables are defined, or the program
neglects to call setlocale, then the default C locale is used, which is
US 7-bit ASCII. On most unix-like platforms, you can get a list of
valid locales by typing the command:
locale -a
at the shell prompt.
Metakeysandlocales
Beware that in most locales other than the default C locale, meta
characters become printable, and they are then no longer considered to
match M-c style key bindings. This allows international characters to
be entered with the compose key without unexpectedly triggering meta
key bindings. You can still invoke meta bindings, since there are
actually two ways to do this. For example the binding M-c can also be
invoked by pressing the escape key momentarily, then pressing the c
key, and this will work regardless of locale. Moreover, many modern
terminal emulators, such as gnome's gnome-terminal's and KDE's konsole
terminals, already generate escape pairs like this when you use the
meta key, rather than a real meta character, and other emulators
usually have a way to request this behavior, so you can continue to use
the meta key on most systems.
For example, although xterm terminal emulators generate real 8-bit meta
characters by default when you use the meta key, they can be configured
to output the equivalent escape pair by setting their EightBitInput X
resource to False. You can either do this by placing a line like the
following in your ~/.Xdefaults file,
XTerm*EightBitInput: False
or by starting an xterm with an -xrm'*EightBitInput:False' command-
line argument. In recent versions of xterm you can toggle this feature
on and off with the "MetaSendsEscape" option in the menu that is
displayed when you press the left mouse button and the control key
within an xterm window. In CDE, dtterms can be similarly coerced to
generate escape pairs in place of meta characters, by setting the
Dtterm*KshMode resource to True.
Enteringinternationalcharacters
If you don't have a keyboard that generates all of the international
characters that you need, there is usually a compose key that will
allow you to enter special characters, or a way to create one. For
example, under X windows on unix-like systems, if your keyboard doesn't
have a compose key, you can designate a redundant key to serve this
purpose with the xmodmap command. For example, on many PC keyboards
there is a microsoft-windows key, which is otherwise useless under
Linux. On my laptop the xev program reports that pressing this key
generates keycode 115, so to turn this key into a compose key, I do the
following:
xmodmap -e 'keycode 115 = Multi_key'
I can then enter an i with a umlaut over it by typing this key,
followed by ", followed by i.

THEAVAILABLEKEYBINDINGFUNCTIONS

The following is a list of the editing functions provided by the Tecla
library. The names in the leftmost column of the list can be used in
configuration files to specify which function a given key or
combination of keys should invoke. They are also used in the next two
sections to list the default key-bindings in emacs and vi modes.
user-interrupt - Send a SIGINT signal to the
parent process.
abort - Send a SIGABRT signal to the
parent process.
suspend - Suspend the parent process.
stop-output - Pause terminal output.
start-output - Resume paused terminal output.
literal-next - Arrange for the next character
to be treated as a normal
character. This allows control
characters to be entered.
cursor-right - Move the cursor one character
right.
cursor-left - Move the cursor one character
left.
insert-mode - Toggle between insert mode and
overwrite mode.
beginning-of-line - Move the cursor to the
beginning of the line.
end-of-line - Move the cursor to the end of
the line.
delete-line - Delete the contents of the
current line.
kill-line - Delete everything that follows
the cursor.
backward-kill-line - Delete all characters between
the cursor and the start of the
line.
forward-word - Move to the end of the word
which follows the cursor.
forward-to-word - Move the cursor to the start of
the word that follows the
cursor.
backward-word - Move to the start of the word
which precedes the cursor.
goto-column - Move the cursor to the
1-relative column in the line
specified by any preceding
digit-argument sequences (see
ENTERING REPEAT COUNTS below).
find-parenthesis - If the cursor is currently
over a parenthesis character,
move it to the matching
parenthesis character. If not
over a parenthesis character
move right to the next close
parenthesis.
forward-delete-char - Delete the character under the
cursor.
backward-delete-char - Delete the character which
precedes the cursor.
list-or-eof - This is intended for binding
to ^D. When invoked when the
cursor is within the line it
displays all possible
completions then redisplays
the line unchanged. When
invoked on an empty line, it
signals end-of-input (EOF) to
the caller of gl_get_line().
del-char-or-list-or-eof - This is intended for binding
to ^D. When invoked when the
cursor is within the line it
invokes forward-delete-char.
When invoked at the end of the
line it displays all possible
completions then redisplays
the line unchanged. When
invoked on an empty line, it
signals end-of-input (EOF) to
the caller of gl_get_line().
forward-delete-word - Delete the word which follows
the cursor.
backward-delete-word - Delete the word which precedes
the cursor.
upcase-word - Convert all of the characters
of the word which follows the
cursor, to upper case.
downcase-word - Convert all of the characters
of the word which follows the
cursor, to lower case.
capitalize-word - Capitalize the word which
follows the cursor.
change-case - If the next character is upper
case, toggle it to lower case
and vice versa.
redisplay - Redisplay the line.
clear-screen - Clear the terminal, then
redisplay the current line.
transpose-chars - Swap the character under the
cursor with the character just
before the cursor.
set-mark - Set a mark at the position of
the cursor.
exchange-point-and-mark - Move the cursor to the last
mark that was set, and move
the mark to where the cursor
used to be.
kill-region - Delete the characters that lie
between the last mark that was
set, and the cursor.
copy-region-as-kill - Copy the text between the mark
and the cursor to the cut
buffer, without deleting the
original text.
yank - Insert the text that was last
deleted, just before the
current position of the cursor.
append-yank - Paste the current contents of
the cut buffer, after the
cursor.
up-history - Recall the next oldest line
that was entered. Note that
in vi mode you are left in
command mode.
down-history - Recall the next most recent
line that was entered. If no
history recall session is
currently active, the next
line from a previous recall
session is recalled. Note that
in vi mode you are left in
command mode.
history-search-backward - Recall the next oldest line
who's prefix matches the string
which currently precedes the
cursor (in vi command-mode the
character under the cursor is
also included in the search
string). Note that in vi mode
you are left in command mode.
history-search-forward - Recall the next newest line
who's prefix matches the string
which currently precedes the
cursor (in vi command-mode the
character under the cursor is
also included in the search
string). Note that in vi mode
you are left in command mode.
history-re-search-backward -Recall the next oldest line
who's prefix matches that
established by the last
invocation of either
history-search-forward or
history-search-backward.
history-re-search-forward - Recall the next newest line
who's prefix matches that
established by the last
invocation of either
history-search-forward or
history-search-backward.
complete-word - Attempt to complete the
incomplete word which
precedes the cursor. Unless
the host program has customized
word completion, filename
completion is attempted. In vi
commmand mode the character
under the cursor is also
included in the word being
completed, and you are left in
vi insert mode.
expand-filename - Within the command line, expand
wild cards, tilde expressions
and dollar expressions in the
filename which immediately
precedes the cursor. In vi
commmand mode the character
under the cursor is also
included in the filename being
expanded, and you are left in
vi insert mode.
list-glob - List any filenames which match
the wild-card, tilde and dollar
expressions in the filename
which immediately precedes the
cursor, then redraw the input
line unchanged.
list-history - Display the contents of the
history list for the current
history group. If a repeat
count of > 1 is specified,
only that many of the most
recent lines are displayed.
See the "ENTERING REPEAT
COUNTS" section.
read-from-file - Temporarily switch to reading
input from the file who's
name precedes the cursor.
read-init-files - Re-read teclarc configuration
files.
beginning-of-history - Move to the oldest line in the
history list. Note that in vi
mode you are left in command
mode.
end-of-history - Move to the newest line in the
history list (ie. the current
line). Note that in vi mode
this leaves you in command
mode.
digit-argument - Enter a repeat count for the
next key-binding function.
For details, see the ENTERING
REPEAT COUNTS section.
newline - Terminate and return the
current contents of the
line, after appending a
newline character. The newline
character is normally '\n',
but will be the first
character of the key-sequence
that invoked the newline
action, if this happens to be
a printable character. If the
action was invoked by the
'\n' newline character or the
'\r' carriage return
character, the line is
appended to the history
buffer.
repeat-history - Return the line that is being
edited, then arrange for the
next most recent entry in the
history buffer to be recalled
when Tecla is next called.
Repeatedly invoking this
action causes successive
historical input lines to be
re-executed. Note that this
action is equivalent to the
'Operate' action in ksh.
ring-bell - Ring the terminal bell, unless
the bell has been silenced via
the nobeep configuration
option (see the THE TECLA
CONFIGURATION FILE section).
forward-copy-char - Copy the next character into
the cut buffer (NB. use repeat
counts to copy more than one).
backward-copy-char - Copy the previous character
into the cut buffer.
forward-copy-word - Copy the next word into the cut
buffer.
backward-copy-word - Copy the previous word into the
cut buffer.
forward-find-char - Move the cursor to the next
occurrence of the next
character that you type.
backward-find-char - Move the cursor to the last
occurrence of the next
character that you type.
forward-to-char - Move the cursor to the
character just before the next
occurrence of the next
character that the user types.
backward-to-char - Move the cursor to the
character just after the last
occurrence before the cursor
of the next character that the
user types.
repeat-find-char - Repeat the last
backward-find-char,
forward-find-char,
backward-to-char or
forward-to-char.
invert-refind-char - Repeat the last
backward-find-char,
forward-find-char,
backward-to-char, or
forward-to-char in the
opposite direction.
delete-to-column - Delete the characters from the
cursor up to the column that
is specified by the repeat
count.
delete-to-parenthesis - Delete the characters from the
cursor up to and including
the matching parenthesis, or
next close parenthesis.
forward-delete-find - Delete the characters from the
cursor up to and including the
following occurence of the
next character typed.
backward-delete-find - Delete the characters from the
cursor up to and including the
preceding occurence of the
next character typed.
forward-delete-to - Delete the characters from the
cursor up to, but not
including, the following
occurence of the next
character typed.
backward-delete-to - Delete the characters from the
cursor up to, but not
including, the preceding
occurence of the next
character typed.
delete-refind - Repeat the last *-delete-find
or *-delete-to action.
delete-invert-refind - Repeat the last *-delete-find
or *-delete-to action, in the
opposite direction.
copy-to-column - Copy the characters from the
cursor up to the column that
is specified by the repeat
count, into the cut buffer.
copy-to-parenthesis - Copy the characters from the
cursor up to and including
the matching parenthesis, or
next close parenthesis, into
the cut buffer.
forward-copy-find - Copy the characters from the
cursor up to and including the
following occurence of the
next character typed, into the
cut buffer.
backward-copy-find - Copy the characters from the
cursor up to and including the
preceding occurence of the
next character typed, into the
cut buffer.
forward-copy-to - Copy the characters from the
cursor up to, but not
including, the following
occurence of the next
character typed, into the cut
buffer.
backward-copy-to - Copy the characters from the
cursor up to, but not
including, the preceding
occurence of the next
character typed, into the cut
buffer.
copy-refind - Repeat the last *-copy-find
or *-copy-to action.
copy-invert-refind - Repeat the last *-copy-find
or *-copy-to action, in the
opposite direction.
vi-mode - Switch to vi mode from emacs
mode.
emacs-mode - Switch to emacs mode from vi
mode.
vi-insert - From vi command mode, switch to
insert mode.
vi-overwrite - From vi command mode, switch to
overwrite mode.
vi-insert-at-bol - From vi command mode, move the
cursor to the start of the line
and switch to insert mode.
vi-append-at-eol - From vi command mode, move the
cursor to the end of the line
and switch to append mode.
vi-append - From vi command mode, move the
cursor one position right, and
switch to insert mode.
vi-replace-char - From vi command mode, replace
the character under the cursor
with the the next character
entered.
vi-forward-change-char - From vi command mode, delete
the next character then enter
insert mode.
vi-backward-change-char - From vi command mode, delete
the preceding character then
enter insert mode.
vi-forward-change-word - From vi command mode, delete
the next word then enter
insert mode.
vi-backward-change-word - From vi command mode, delete
the preceding word then
enter insert mode.
vi-change-rest-of-line - From vi command mode, delete
from the cursor to the end of
the line, then enter insert
mode.
vi-change-line - From vi command mode, delete
the current line, then enter
insert mode.
vi-change-to-bol - From vi command mode, delete
all characters between the
cursor and the beginning of
the line, then enter insert
mode.
vi-change-to-column - From vi command mode, delete
the characters from the cursor
up to the column that is
specified by the repeat count,
then enter insert mode.
vi-change-to-parenthesis - Delete the characters from the
cursor up to and including
the matching parenthesis, or
next close parenthesis, then
enter vi insert mode.
vi-forward-change-find - From vi command mode, delete
the characters from the
cursor up to and including the
following occurence of the
next character typed, then
enter insert mode.
vi-backward-change-find - From vi command mode, delete
the characters from the
cursor up to and including the
preceding occurence of the
next character typed, then
enter insert mode.
vi-forward-change-to - From vi command mode, delete
the characters from the
cursor up to, but not
including, the following
occurence of the next
character typed, then enter
insert mode.
vi-backward-change-to - From vi command mode, delete
the characters from the
cursor up to, but not
including, the preceding
occurence of the next
character typed, then enter
insert mode.
vi-change-refind - Repeat the last
vi-*-change-find or
vi-*-change-to action.
vi-change-invert-refind - Repeat the last
vi-*-change-find or
vi-*-change-to action, in the
opposite direction.
vi-undo - In vi mode, undo the last
editing operation.
vi-repeat-change - In vi command mode, repeat the
last command that modified the
line.

ENTERINGREPEATCOUNTS

Many of the key binding functions described previously, take an
optional count, typed in before the target keysequence. This is
interpreted as a repeat count by most bindings. A notable exception is
the goto-column binding, which interprets the count as a column number.
By default you can specify this count argument by pressing the meta key
while typing in the numeric count. This relies on the digit-argument
action being bound to Meta-0, Meta-1 etc. Once any one of these
bindings has been activated, you can optionally take your finger off
the meta key to type in the rest of the number, since every numeric
digit thereafter is treated as part of the number, unless it is
preceded by the literal-next binding. As soon as a non-digit, or
literal digit key is pressed the repeat count is terminated and either
causes the just typed character to be added to the line that many
times, or causes the next key-binding function to be given that
argument.
For example, in emacs mode, typing:
M-12a
causes the letter 'a' to be added to the line 12 times, whereas
M-4M-c
Capitalizes the next 4 words.
In vi command mode the Meta modifier is automatically added to all
characters typed in, so to enter a count in vi command-mode, just
involves typing in the number, just as it does in the vi editor itself.
So for example, in vi command mode, typing:
4w2x
moves the cursor four words to the right, then deletes two characters.
You can also bind digit-argument to other key sequences. If these end
in a numeric digit, that digit gets appended to the current repeat
count. If it doesn't end in a numeric digit, a new repeat count is
started with a value of zero, and can be completed by typing in the
number, after letting go of the key which triggered the digit-argument
action.